1. Field of the Invention
The present invention relates to an apparatus and method for receiving Protocol Data Units (PDUs). More particularly, the present invention relates to an apparatus and method for simultaneously receiving a plurality of PDUs.
2. Description of the Related Art
With the advance of mobile communication technology, portable terminals are now able to provide users with voice communication services as well as the ability to transmit and receive data. As users become more sophisticated and more demands are made for enhanced services, service providers are considering new ways to provide data communication at higher speeds.
The 3rd Generation Partnership Project (3GPP) is currently standardizing a technology known as Long Term Evolution (LTE) to provide higher speed data communication. LTE is a broadband packet-based communication technology which is expected to be commercially available in 2010 and provide downlink data communication speeds of up to 100 Mbps. To achieve such high speed data rates, an LTE system minimizes the number of involved nodes in the connection.
In the provision of a data service, resources are allocated after considering the amount of data to be transmitted and the status of the channel. Accordingly, a wireless communication system is provided with a scheduler to manage the resource allocation in consideration of the available resources, channel status, quantity of transmission data, and the like. Such resource scheduling is required in LTE as one of the next generation mobile communication systems, and a scheduler incorporated in a base station is responsible for management of radio transmission resources.
In an LTE system, data is transmitted in a unit of Transport Block (TB) or Media Access Control Protocol Data Unit (MAC PDU) with a Transmission Time Interval (TTI) of 1 msec. Typically, a single MAC PDU is transmitted in a single TTI and the protocol layers of LTE have been designed under this assumption. However, as the LTE standards have evolved, there have been discussions regarding the use of multiple downlink and uplink channels for a User Equipment (UE) to receive and transmit data. In such an evolved communication environment, a UE can transmit and receive multiple MAC PDUs and thus multiple Radio Link Control (RLC) PDUs can be received on a logical channel. Accordingly, there is a need to develop a method and device that can operate appropriately for receiving a plurality of RLC PDUs simultaneously.